There is nothing more awe inspiring than nature. Today I came across the image below at the [Astronomy Picture of the Day](http://apod.nasa.gov/apod/ap090203.html) on the NASA site.
The [Crystalinks site](http://www.crystalinks.com/lenticular.html) has this definition:
Lenticular clouds, technically known as altocumulus standing lenticularis, are stationary lens-shaped clouds that form at high altitudes, normally aligned at right-angles to the wind direction.
Where stable moist air flows over a mountain or a range of mountains, a series of large-scale standing waves may form on the downwind side. Lenticular clouds sometimes form at the crests of these waves. Under certain conditions, long strings of lenticular clouds can form, creating a formation known as a wave cloud.
The image below is from the NASA site, there are [more pics](http://www.crystalinks.com/lenticular.html) on the Crystalinks site.